Computer systems generally include multiple agents, such as microprocessors, storage devices, display devices, etc., which are interconnected via a system bus. The system bus operates to transfer address, data and control signals between these agents. Certain computer systems employ multiple busses, in which various agents are coupled to one or more busses. Typically, each agent is coupled to a single bus.
Bus bridges are often utilized in multiple-bus systems to connect the busses and thereby allow agents coupled to one type of bus to access agents coupled to another type of bus. The function of the bus bridge typically involves transferring commands between two busses. The commands transferred by the bus bridge often have data associated with them (e.g., read or write commands).
One problem which frequently arises in computer systems with multiple agents is a need to preserve transaction ordering. Thus, a bus bridge in a multiple-bus system must address the problem of transaction ordering. Although various bus bridge implementations exist in the art, it is believed advantageous to provide a method and system which resolves the transaction ordering problem in a more effective and efficient manner than previously known. The present invention provides such a solution.